Specs for 240v outlet/breaker

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leaferikson

New member
Joined
May 10, 2018
Messages
3
Hi, I'm getting my new, 2018 Leaf SL next week and I am having trouble figuring out EXACTLY what specifications are required for the double pole circuit breaker and 240v outlet. I would like to be able to charge at the max, which I believe is 6.6kwh. I've tried very hard to find a post with a clear and concise answer, but most threads I've found relate to upgrading existing 220/240v outlets.

To be clear, I would be thrilled/appreciative if the following could be answered concretely, as I'm having anxiety regarding getting this installed before I bring the leaf home. Mind you, I don't know anything about electrical work, but I want to be able to make sure a hired electrician is installing the correct equipment.

1. What amperage for the double pole circuit breaker? 50 amps?

2. What NEMA rating for the outlet? 14-50? AND is a 250v outlet ok? That seems to be what home depot/lowes sells.

This? https://www.lowes.com/pd/Utilitech-50-Amp-125-250-Volt-Black-Indoor-Round-Wall-Range-Power-Outlet/3775483

3. What gauge electrical wire?

Thanks again in advance. I did spend about 1 hour searching/googling. Honest!

EDIT: The search function works a lot better in these forums than google. I think I found my answer, but if anyone feels like answering here it would still be appreciated.
 
I don't think you will be sorry going with the following DEDICATED circuit for your portable EVSE that comes with the 2018 Leaf SL:
1) 50a 240v breaker
2) NEMA 14-50R outlet (I don't think the nominal voltage matters)
3) NM-B 6/3 AWG
Some may say this is more than you need currently, but at least you should sleep well not worrying about adequacy -- and it may pay off in the future in not having to upgrade the circuit.
BTW, I believe that EVSE's cord is about 18 ft in length, so plan the location of your outlet carefully.

I'm adding this here (rather than in a distant additional post):
4) Strongly suggest using a lockable cover (inexpensive) over the receptacle (and always lock it), in order to make it as safe as possible in the way a direct wired EVSE is. This is especially true if you never (or rarely) move the EVSE.
 
Concur with MikeD. The outlet you linked is correct. If the wire run is in conduit, your electrician will probably run 4 separate wires rather than 1 NM-B cable. The ground wire (bare or green) can be 10AWG like it is in the NM-B 6/3 AWG cable.
 
Thanks again for the responses. My goal is to have all of the supplies for the job on sight when my electrician friend comes - he'll be doing it as a side job.

Is this wire ok?

Cerrowire 147-4203A 25-Feet 6/3 NM-B Stranded with Ground Wire, Black https://www.amazon.com/dp/B00IKVLC62/ref=cm_sw_r_cp_apa_i_4PA9AbEYSY8Y9

And this breaker?

https://low.es/18Flye7

Thanks guys, much love.
 
leaferikson said:
Thanks again for the responses. My goal is to have all of the supplies for the job on sight when my electrician friend comes - he'll be doing it as a side job.

Is this wire ok?

Cerrowire 147-4203A 25-Feet 6/3 NM-B Stranded with Ground Wire, Black https://www.amazon.com/dp/B00IKVLC62/ref=cm_sw_r_cp_apa_i_4PA9AbEYSY8Y9

And this breaker?

https://low.es/18Flye7

Thanks guys, much love.
It depends on where he's installing the wire. NM-B is generally installed inside the drywall. If you're installing in conduit on the wall, then you want individual wires.
 
You don't even need an outlet if you get a hardwired EVSE. You need 40 amp circuit and 32 amps charging to go full power. You can go bigger it just will not get utilized. 240 x 32 = 7.68 kW. 40 amp circuit #8 wire is fine.

https://store.clippercreek.com/level2/level2-20-to-32/hcs-40-hcs-40p-ev-charging-station

Honestly I think most would be fine at 24 amps requiring just a 30 amp circuit. 5.76 kW. 30 amp circuit #10 wire is fine.

https://store.clippercreek.com/level2/level2-20-to-32/lcs-30-24-amp-ev-charging-station
 
leaferikson: There is one more (somewhat controversial) thing to consider about the breaker choice, i.e. whether or not it is a GFCI type.
From the "2018 Leaf Owner's Manual": " In order to avoid an electric shock or fire due to a short circuit, connect to a GFI (Ground Fault Interrupter) circuit breaker and use a waterproof electrical ground socket."

Downsides:
1) It costs significantly more (at about $100).
2) There may be a risk of "nuisance tripping". If using one results in a frequent such problem (that cannot be remedied), one may have no choice but to use a non-GFCI breaker.
Upsides:
1) It does significantly reduce the possibility of a serious accidental shock while plugging/unplugging, especially if you do this frequently within reach of a (low resistance) ground.

Update to original post:
Partly for testing purposes I have acquired a portable Nissan L1/L2 EVSE designed for use in a 2018 Nissan Leaf (part # 29690-5SA0A), wired it up (temporarily) with a Square D 50a 240v GFCI (part # QO250GFICP) breaker, 70 feet of NM-B 6/2 AWG cable, and a NEMA 14-50R receptacle and then test charged my 2011 Leaf with it multiple times now with no problems -- especially no nuisance tripping. If I were installing the wiring permanently, I would have bought and used 6/3 cable because I think it would be safer (i.e. the circuit is "complete" for any future use).
 
GFCI is dictated by applicable code . A proper one if required should not trip inappropriately. The LEAF manual is irrelevant as it has no relevance to your local code.
 
It really depends on the current. A 40A outlet would have #8 L wires. A real 50A outlet would have #6 L wires. For most EVSE's a 40A circuit is fine. It should be labeled 40A instead of the rated 50A. I have one of the few cars that require a 5oA circuit. I charge at 40A. An enhanced Leaf charges at 27,5A so a 40A circuit is fine. The basic S draws 16A. It will work fine on a 40A circuit but it is overkill.
 
National standards do not require ground fault circuit interrupter (GFCI) breakers for 50-ampere, 240-volt receptacles (local codes may be more stringent). All 15- or 20-ampere, 240-volt receptacles installed in garages or outdoors should be protected by GFCI breakers since they could be used for air compressors, power tools, or other cord and plug-connected equipment. EVSEs that comply with national codes and standards have internal ground fault protection and their supply cords are a maximum of 12 inches in length so you should have your EVSE available and determine the mounting location before installing a new receptacle for it. Follow branch circuit requirements noted in the EVSE installation instructions.

Some 30-ampere (or higher), 240-volt EVSEs which are intended for permanent mounting (whether plug-connected or hard-wired such as the AeroVironment unit I purchased in 2011) will trip standard GFCI breakers because they pass a small leakage current as a method to test the equipment ground connection. I had to replace a GFCI breaker with a standard 40-ampere breaker to use my AeroVironment EVSE. Any EVSE that is truly intended to be portable should be suitable for use with a receptacle that matches its plug protected by a GFCI breaker of appropriate current rating.
 
GerryAZ said:
Building codes do not require ground fault circuit interrupter (GFCI) breakers for 50-ampere, 240-volt receptacles. All 15- or 20-ampere, 240-volt receptacles installed in garages or outdoors should be protected by GFCI breakers since they could be used for air compressors, power tools, or other cord and plug-connected equipment. EVSEs that comply with national codes and standards have internal ground fault protection and their supply cords are a maximum of 12 inches in length so you should have your EVSE available and determine the mounting location before installing a new receptacle for it.

Some 30-ampere (or higher), 240-volt EVSEs which are intended for permanent mounting (whether plug-connected or hard-wired such as the AeroVironment unit I purchased in 2011) will trip GFCI breakers because they pass a small leakage current as a method to test the equipment ground connection. I had to replace a GFCI breaker with a standard 40-ampere breaker to use my AeroVironment EVSE. Any EVSE that is truly intended to be portable should be suitable for use with a receptacle that matches its plug protected by a GFCI breaker of appropriate current rating.

So you are familiar with all local building codes in all US cities? Have you been on many inspections with local inspectors and seen the type of crazy things they require on outside and garage outlets ? Not to mention some local arc fault requirements. I've experienced far too many painful experiences on inspections not based on reason.
 
EVDRIVER and smkettner,

Thanks for calling me out on the misleading statement. I have edited my earlier post to avoid misleading anyone. GFCI breakers provide additional safety if the equipment being installed is compatible. Unfortunately, there are some 240-volt EVSEs that are not compatible with standard GFCI 2-pole breakers.
 
Is a dedicated hard wired EVSE circuit w/ a GFCI breaker significantly safer than one w/o? If not for shock protection, what about for fire prevention?
 
MikeD said:
Is a dedicated hard wired EVSE circuit w/ a GFCI breaker significantly safer than one w/o? If not for shock protection, what about for fire prevention?
afaik the EVSE should have GFCI protection already. No need for belt and suspenders IMO.
 
smkettner: It is my understanding that the GFI protection that an EVSE provides is only "downstream" from its control unit and so not at the plug input end (which is "upstream" from the control unit).

Excerpt from the Siemen's Versicharge "Installation and Operations Manual":
"The Siemens VersiCharge line of EV Charging Systems includes a Charging Circuit Interrupting Device (CCID). The CCID is required by UL Standard 2231 and is designed to detect grounding faults within the system [I believe "system" is referring to its EVSE], and disconnect power from the downstream conductors when a fault is detected".

How could an EVSE disconnect power at its input plug end?

So assuming the charging cord remains intact the GF protection is of importance only at the exposed conductors within the J1772 plug -- which should normally be electrically hot only after plugging in/before unplugging from the EV (so normally not directly touchable). Also I believe a typical GFCI allows only about 6ma of current as opposed to usually 20ma of current at the J1772 output end -- i.e. a GFCI stops the duration of voltage shock significantly faster. It is possible that EVSE's have changed in this regard (specs don't always document this issue). I think EVSE manufacturers may be struggling with "nuisance tripping" issues -- an EV owner won't be happy with an EVSE that GF trips frequently -- even if it resets and continues. And some circuit issues that cause sporadic GFs, like insufficient circuit wire insulation integrity that can allow too much current leakage, are beyond the control of the EVSE design.

I just found this additional excerpt"
"Nuisance fault: As a leader in electrical technology, Siemens has made the decision to install 5 mA grounding protection in all VersiCharge devices. This is the same level of protection that is required in kitchens and bathrooms of residential dwellings. Some other manufacturers (EVSE and Auto manufacturers) have selected 20 mA protection levels. Because Siemens units measure to a more sensitive level, occasional charging interruption may occur under certain circumstances."
 
I have no concern of power leakage at the power plug. If plugging in during driving rain with everything soaked just take a bit of extra precaution. Non-issue indoors. Non-issue with hardwired EVSE.
 
smkettner: Suppose some curious visiting headstrong children unplug that EVSE...?
Suppose you have metal conduit leading to that receptacle -- NEC requires that conduit be grounded. How easy is it to momentarily accidentally touch one of the two (long) hot prongs of a 14-50 plug with the fingers of one hand while resting the other hand on the conduit?
Ever get momentarily dizzy? The odds are small, but multiply that by the tens of millions that I hope trade their ICE cars for EVs soon, so I hope the odds are made to be even smaller.

I am with you on having EVSEs being hardwired if at all possible!
 
That said, why would the Leaf EVSE short in a professionally installed 14/50 circuit? I can only think of 2 things: 1) the evse is no good ( even though it works on 110 after the short) or 2) the EVSE doesn’t want a neutral - some none standard reason. Can anybody help? Planning on taking the EVSE to Nissan tomorrow.
 
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